My experience has been they will take you as a volunteer if you are willing to separate from your luggage, but there is a nearly 100% chance your bags will be mishandled and arrive at your destination a full day late. :|

I strongly recommend carry on only for international VDB. If you get rerouted, it's likely your bags won't be rerouted on the same flights and won't travel on your original flights. For most DL routes, missing the flight you were originally booked on means a full day delay...